Machine for forming sheet-metal elbows



spt. 15,!1925.

C. J. HOLUB IACHINE FOR FORMIG 'SHEET METAL ELBOWS sept. 15, 192s.' 1,553,817l

C. J. HOLUB CHINE FOR FORIING SHEET METAL ELBOWS Filed lay 16, 192g?- '7 Sheets-Sheet 2 sept. 15, 1925.

C. J. HOLUB MACHINE FOR FORMING SEEE?` METAL ELBOWS med may 1e, 1925 7 Sheets-Shut 3 sept. 15, 1925 1,553,817

C. J.- HOLUB MACHINE FOR FORMILNG SHEET METAL ELBOWS Filed May 16I 1923 '7 Sheets-Shao?. 4

` 1` i ZY 'ff wo @j n 1 1'/ l 530 7e M n 0 f-L; 57 40 sept. les, 192s.

'7 Sheets-Shen 5 Filed May 16, 1923 Sept. 15, 1925. 4 1,553,817

c. J. HOLUB CHINE FOR FORMING SHEET METAL ELBOWS ylriidrmy 16v, 1923 'r sheets-sheet 6 .lllulllullul 'IIIIIIIIIIMIM va 1' MIIHIIIII Sept. 15, 1925. 1,553,817

- c. J. HoLuB MACHINE FOR FORMING SHEET METAL ELBOWS 7 Sheets-Sheet 7 med May 16, 192s -ing mechanism for facility Patented Sept. 15, 1925.

A V1,553,817 f UNITED? STATES lPATENT OFFICE. E

camas J. noLUB, or coLumBUs, onto,

NECK AND ONE-THIRD T0 A.

assIGNon or ONE-THIRD To w. E. Lm-

LAMNEcx, BOTH or coLUnBUs, omo.

MACHINE FOR FORMING SHEET-METAL ELBOWS.

Application led Hay 10,

To all 'whom 'it may concern:

Be it known that I, CHARLES J. HoLUB, a citizen of the United States, and residing at Columbus, in the county of Franklin and State of Ohio, have invented a new and useful Im rovement lin Machines for Forming Sheet-liletal Elbows, of which' the following specification is a full disclosure.

This invention relates to an improved machine for producing corru ated stove pipe elbows, in which the mec anism operates upon a sheet metal tube or pipe section to clrcumferentially corrugate the same, and as the corrugatons are successively made the tions to the desired elbow an le.

The primary object of the invention is to provide a machine in which the mechanism 1s susceptible to high speed operation for increasing the capacity production of the machine, and which is automatic in its operation after manually loaded and started, and readily ad'ustable for making diierent pi sizes of el ows.

Iether objects of the invention relate to improvements in the corrugating mechanism for geometrically forming each corrugation, and for expandin and compressing portions thereof in a ben ing operation for the production of an elbow, and to the bendin loading and unloading of the machine.

Other objects and features relate to improvements in the mechanism for automatic control of the-machine, in simplifying the construction of the machine, increasing its durability and avoiding complication heretofore experienced in machines of this class, all of which will be more fully disclosed in the following description of the accompanying drawings forming a part of this specifcation, in which:

Figure 1 is a side elevation of the improved sheet metal elbow-forming or pipe corrugating machine.

Fig. 2 is a section on line 2`-2, of Fi 1. Fig. 3 is an enlarged top plan view o the machlne. p

Fig. 4 is an enlarged section on line 4-4, of Fig. 2.

Fig. 5 isa section on line 5--5, of Fig. 4. Fig. 6 is a front end face viewof the machine with the `bed omitted and a ortion broken away* and shown in Section or the en vtu tube is progressively bent at thecorrugayfo 1923. Serial lo. $9,411.

Fig. 6.

1g. 11 is a side elevation of an end tool adapted to adjust the corrugating dies or Jaws.

1gaged upon t e end of the sheet metal mg to be corrugated or bent into elbow Fig. 13 is an end view thereof.

Fig. 14 is a side view.

Fig.' 15 is a. section on line15-15, of Fig. 3.

Fig. 16 is a section on line 165-16, of F1 3.

Fig. Fig. 16;

18 is a section on line 18-18, of

e machine operates upon a. sheet metal bent to tubular or pipe orm for corru tin the tubing circumferentially and t en nding the tubing in the form of an elbow at the corrugations, as illustrated in Fig. 8. The bending operation crimgis the metal of each corrugation upon itsel at a. portion of the tube dlameter and at an opposite portion expands the corrugation and to a de for producing the desired angle bend o elbow, the bending operation belng subsequentto each corrugating operation, so that the tubing is progressively corrugated and bent. After each corrugation' is formed ,the sheet metal tube is advanced to the yrequired degree for a second corrugation, essary for the formation of the desired angle elbow. The bending of the tube into elbow form, as corrugated, is accomplished by means of a bending to and about one end ofthe tube, the head cooperating with a pair of arms oscillating as aounit atl an angle to thedirection ofthe tube feed. The arms are arranged to swinv apart, facilitating the manual insertion an wlthdrawal of t eQtube or elbow and attached headto and from the machine. A For loading the machine the tube is engaged 17 'is asection on line 17-17, of

iece of Fig. 12 is a 1an view of a cam collar L and bent to a degree nechead or ring applied with the carriage, and the carriage is retreated as the tube is manually pushed into the machine. As the' carriage reaches the limit of its retreat stroke the tube is automatically locked to the carriage and likewise automatically released as the carriage reaches its forward traversing limit. Likewise the transmission mechanism is automatically controlled through the movements part of the present invention,

of the carriage, so that the machine is started after the tube has been vinserted and stops after the carriage has been moved to its forward limit. This greatly facilitates the operation of the machine to the relief of the operator.

Referring to the drawings, 1 indicates the bed of the machine, which may be of any conventional form, upon which a transmission mechanism and corrugating and bending mechanism is mounted. The transmission mechanism is mounted to occupy one end of the bed, and the corrugating and bending mechanism, the opposite end of the bed. The' transmission mechanism comprises bearing brackets 2, 3, spaced a art and mounted upon the upper surface o the bed for journalling the power shaft 4, having a pulley 5 fixed thereon at one end. spur pinion 6 is mounted upon and fixed to the shaft 4 and located between the bearings 2, 3, and in mesh with a larger diameter gear wheel 7 loosely mounted upon a coun- -tershaft 8 journalled in elevatedbearings of the journal brackets 2, 3. The ar wheel 7 is connected to the shaft 8 by clutch mechanism manually and automatically controlled, the 'mechanism of which will be more fully hereafter described. The clutch for the gear wheel 7 may be of any type of construction, friction or toothed, the type of clutch employed specifically forming'` no except only in so far as the' control or operation thereof is pertinent to the control and operation of the corrugating and bending mechanism.

j Arising vertically from the bed 1 and disposed adjacent to the bearing 3 is a vertical frame wall 9, providing bearings for a plurality of shafts disposed about the axis of the countershaft 8, which has an end bearing in said frame wall 9, as shown in section in Fig. 4. The shaft 8 is provided with a spur gear 10=keyed thereto and in mesh with'four gears,"11, 12, 13 and 14, respectively fixed upon the ends of shafts 15', 16, 17 and 18, .suitably disposed about the gear 10 to provide independent transmissions for each of a plurality of dies or plungers for circumferentially corrugating the tubing disposed between the dies'.

The clutch for connecting gear 7 to the upon the shaft 8, and consists of the followin parts: The shaft 8 has an enlarge diameter portion 19 as a hub and A ing engaged ably receive a retractable latch bar 21,A

the latch bar being held in place within the groove by a colla-r 22 engaged about the periphery of the hub 19, the collar being slotted to provide an opening through which a lateral projection 23l of the latch bar projects. The latch bar is engaged by a spring 24 confined within the groove in the hub by a washer or plug 25 against which the spring 24 engages, the spring urging the latch bar outwardly for engagement with either of the ins 26-26, laterally projecting from the lub portion of the gear 7 for connecting the gear 7 with the shaft. The latch bar is actuated by a cam shoe 27 mounted upon an arm 28 pivotally connected to 'a bracket plate 29 fixed to the side of the bearing 3. The arm 28, at its forward end, is pivotally connected with a link 30, the link in turn beingl connected to an arm 31 engaged upon an actuator rod 32. The arm 28 has a branch extension 33to which a spring 34 is connected, one end of the spring being engaged in the head of a screw 35 and in threaded engagement with the branch 33, the opposite end of the spring beto 4the bracket plate 29, the sprinvI urging the arm 28 upwardly to bring the sioe mounted `thereon in engagement with the latch bar for disconnecting the, gear 7 from the Vshaft 8.

The actuator rod 32 is engaged through and journalled in the wall 9, and extends forwardly, and its forward end engaged and journalled in a front frame wall 36, upon which the dies for ccrrugating the sheet metal tubing are mounted. The actuator rod is operated by a carriage, to which the sheet metal tube to be formed into an elbow,

Vis connected, the carriage advancing in step degrees upon a mandrel between the front wall 36 and rear wall 9.

Carriage and eawage feeding mechanism.

The inner frame wall 9 is formed to include a pair of spaced lugs 37, between which the projecting ear 38 of the collar 39 is pivotally engaged, the collar providing a pivoted head for a horizontally exten ed mandrel or core 40. The mandrel 4 0 is situated in axial alignment substantially with the counter/shaft-S and is adapted to have its outer end received within an opening 1n the outer or front frame w'all 36. The collar 39 carries a set screw 41 engaged therethroughv and into the rear frame wall 9 for rigidly securing the mandrel to the frame wall, the set screw also providing means for making ave the set screw merely engage the frame wall 9, which vwouldV permit the mandrel toy swing vertically, for centering itself'between and under the pressure of the opposingly the desired axial adjustment of the mandrel, vertically. It is also vfeasible to. i shaft 8 1s disposed between gears 7 and 10 h In the Vmanufacture of commercial sizes of stove pipe elbows, the mandrel is of a length which will permit it to flex sufliciently for centering between the dies, permit-ting the head of the mandrel to be rigidly secured to the frame wall 9.

The mandrel longitudinally is provided with a spline groove for receiving a slidab-le ratchet bar 42, having ratchet teeth 43 along its upper edge, the teeth of a pitch to ob` tain the desired degree of carriage step advance required. for the proper corrugation spacing in a determined size of elbowvto be roduced. The ratchet bar is removable to )e interchanged for other tooth gauge bars to change the degree of carriage step advance. The inner or rear end of the ratchet bar 42 connects to a spring pressed plunger slidably supported in and engaged through the rear frame wall 9, for reciprocating the ratchet bar. The plunger' consists of a yoke member 44 having cylindrical limbs respectivelyengaged in and through bores inthe frame wall 9. .The limbs areconnected by a cross plate 45 recessed into the mandrel head collar 39 and connected to a ratchet bar by a pair of tie bars 46 Vsecured to the opposite sides of the cross plate 45 and depending therefrom and secured to the end of the ratchet bar (see Figs. 4 and 5). The plunger carries a roller 47 engaging a cam ring 48 fixed to the side of the gear wheel 10 upon the countershaft 8. The cam f ring with each cycle of the gear 10 pushes the plunger and the ratchet bar. 42 forwardly forl producing a step advance of the carriage in timed relation to the operation of the corrugat-ing dies. The carriage advances intermittently for producing the corrugations Singlyin-'a serial order and for successively bending the tube at each previously formed corrugation while'the tube is clenched between thedies. The se uences are at a high rateof -frequency enabling the rapid and eflicient production of an elbow, and the tube is advanced in a direction of withdrawal from the machine, making it commodious to the operator for removing the finished' elbow and inserting a second blank tube.

The plunger and its roller are 4 yieldably held into engagement with the cam ring by a pair of coil springs49-49 respectively engaged upon rods 50-50 secured to and projecting from the rearframe wall 9, one end of said spring engaging' against a cross bar 51 straddling and engaging the plunger plate 45 and slidably engaged upon the`1ods50-50.l Each rod is provided with nuts threaded upon the end thereof engaging the opposite end of the spring, and by means of which the tension of the spring can be regulated. A carriage 52 is arranged to slide longitudinally of and upon themandrel and `to which one end of the sheet metal tube to be corrugated and formed into an elbow is connected. The carriage preferably is formed of a pluralit of concentrically engaged or nested di erent diameter collars secured together as a unit, and, as shown,

comprises three collars, 53, 54 and 55, .the`

inner one of which is provided with a spline groove to receive the ratchet bar 42, and diametrically opposite the groove carries a key 56 engaged with a spline groove formed in the mandrel for the,purpose of nonrotatively sustaining the carriage upon the mandrel. The inner collar 53 peripherally at one end is counterturned, while the second collar 54 is correspondingly counterturned externally andcounterbored internally, the counterbore mating with the counterturned. periphery of the' inner collar to provide anf annular recess 57 between the two collars serving as a socket to receive the end of a length of pipe tubing for a determined pipe diameter. counterbored to mate with the counterturned periphery of the second collar, forming a second ipe receiving recess or socket for a secon size of pipe tube. Thus a plurality of dilferent sizes of pi e can be socketed into the head, and sai head may be enlarged upon to accommodate any number of different sizes of pipe.

The pipe is locked within and to the carri# age by a pin 58, and for the size of pipe tube length shown in the drawing, which is engaged with the socket formed between the second and third collars-54, 55, the pin 58 is engaged transversely through an aperture in the collar 55 so as to be accessible by a cam or wedge bar'or member 59 slidable within a longitudinal groove formed The third collar 55 isv within the bracket memberGO yoked to be'V ally or automatically at the opposite ends of the carriage traverse upon the mandrel. At the end of the carriage forward traverse the stem engages a projecting finger 63 fixed to the rear sideof the front wall 36, which with the carriage advance moves the wedge bar 59 rearwardly to release the lock pin 58, and is again depressed after the carriage has been moved to its retreat or starting position, by engaging an arm 63* (see Fig. 3) adjustably secured upon and projecting nfrom a rod 63" longitudinally parallel with the mandrel 40 and secured to and extending from the front side of the rear frame wall 9.. Thus the wedge bar 59as a slide boltis operated at the forward and return limits of carriage traverse, matically locking an'd alternately releasing the pin 58k autoe llt) the pipe tube length from the carriage. The4 end of the slide or wedge bar 59 which engages the head end of the lock pin 58 is appropriately formed to wedge to force t e in inwardly, the pin biting into the pipe, and to hold the pm in such position until positively released. The collars 54 and 55 are provided with registering apertures 58L through which a pin of appropriate length is inserted for locking the pipe tube length within the socket 57 formed between the collars 53, 54. Providing separatepin aper tures for each diameter of socket enables the pin to pressl the tube metal against the surface of the socket so that there is no liability of puncturing the metal.

The carriage is intermittently traversed by aspring vpressed pawl 60a slidable in a slot in a bracket 52* of the carriage and held therein bythe bracket 601 for engaging with the teeth of the ratchet bar 42. The upper end of the pawl 60*l is engaged b a leaf spring 64 vfixed to the bracket 52 o the carriage. The pawl 60* under a depressing tension is urged upon the ratchet bar 42 for pawl enga ement with a registering tooth shoulder o the ratchet bar. Thus as the ratchet bar 42 is moved in a forward. stroke by the plunger engagement with the cam surface of the cam r1ng 48 upon the ear wheel 10 the carriage 52 is traversed a efinite step de ee. U on the return stroke .of the ratchet ar 42 t e pawl 60 is expressed to ride over the teeth. The carria e 52 is under retrograde pressure whereby t e pawl 60* is firmly retamed against the shoulder of a ratchet bar tooth with which the pawl is in registration, preventing any overthrow of thecarriage in a forward or feeding diand over an idle sprocket rection and automatically retreating the 4carriage when the pawl is moved positively out of tooth engagement. This action of the carriage is accomplished by means of a weight 65 slidably sustained within a guide hanger 65* depending from the bed. (See Figs. 1 and 2.) The weight 65 is connected to a sprocket chain 66 extending upwardly wheel 67 journailed. within a bracket 68 fixed to thegforward side ofthe rear frame wall 9, and there connects to an eye screw threaded into the carriae. The weight at opposite sides is provi ed with straps 69--69 to which one end of the coil'sprmgs 70-70 respectively are connectedythe opposite end connecting' with a cross bar 71 fixed to the'cross rails of the guide hanger 65.

' mentalities:

The pawl 60* is positively actuated for throwing the same out of engagement with the ratchet bars releasing the carriage for its retreat stroke and automatically thrown into commission by the following instru- A latch bolt 72 is `inountediin a. slot in the bracket 60?, slidable transversely to the notch provides an' inclined surface for en-4 pin 74 to elevate yor gaging beneath the the latch bolt is reciplower the pawl 60'L as rocated. engaged by an arin One end of the latch bolt 72 is- 76 fixed upon the axis l of a hand lever 77 pivoted upon the ear 78 extending from the bracket 521? on the carriage. The swing of the arm 76 is confined in outward direction by ain 79 fixed to and extending from the brac et 52. As the hand lever 77 is manually actuated to swing the arm 76 forwardly toward the end o the latch bolt 72, the latch bolt is slid in such direction wedgingv the pawl 60 upwardly out of engagement with the ratchet bar 42 and sustained in said retreated position until the position of the latch bar is reversed. The end of the latch bolt 72 opposite the latch shiftingarm 76 has an extension 80 with a beveled end for engage-y ment with the trip dog 91 adjustably secured. upon the rod 63 upon whic the arm 63 is mounted for actuating the slide bolt` 59 for locking the pipe tube within and to the carriage. Thus if the pawl latch bolt 72 is positioned to sustain the pawl out of commission upon the retreat traverse of the carriage, the inclined or beveled-end 8O of the latch bolt is extended to engage with the stationary trip dog 91, which forces the latch bolt inwardly, permitting the pawl when its pin 74 is in registry with the notch 73 to snap into engagement with the ratchet bar.

The carriage at the end of its strokes also controls the operation of the transmission gearing through the control of the' clutch mechanism previously described, connecting transmission gear 7 with the shaft 8. The rotation of the shaft 8 is ydiscontinued at the limit of the carriage forward traverse and remains at rest until the carriage has been moved to its full retreat position for the -size of the pipe tube operated upon. The carriage 52 remains in its full forward osition until the carriage pawl 60'I has een manually released from the ratchet bar 42 and this usually after the -pipe tube length has been engaged in the carriage so with either of the trip'dogs 94, 95, mounted 4upon the shifting rod 96 slidably supported at its -o 'posite ends upon bracket lugs 97, 98, respectively fixed to and projecting in opposite directions from the front and rear frame walls 9 and '36. The trip .dog 94 is rigidly connected to one end of the shifter bar or rod 96 and is provided with an upstanding stem 99 to furnish a hand grip for manually f pipe tube. ,Each die has its individual actu- 'its forward traverse.

Clutch operation and transmfleaion atop control.

In the retreat traverse of the carriage the bracket reach 93 engages the adjustable trip dog 95 appropriately set .upon the shifter bar 96. The opposite or rear end of the shifter bar 96 has a tri dog 103 rigidly attached thereto and sliably engaged upon the bracket lug 97 as described for the forward end of the shifter bar in connection with the lug 98. The trip dog 103 has a tail extension 104 carrying a beveled shoe engaged with an inclined edge of an arm 105 fixed upon the rock shaft or rod 32, journalled in the frame walls 9 and 36, the rock shaft, as previously described, operating the cam shoe 27 of the transmission clutch mechanism. The arm 105 isprovided with a hand grip stem 106 for manually actuating the rock shaft 32 from the side of the machine.

O'ofrmgatzng mechanism.

The corrugating mechanism embodied in the machine (see Figs. 6, 9 and 10), comprises a plurality of diesl arranged in diametrically opposing pairs upon the front frame wall 36 and reciprocating radially from the axis of the mandrel which'is disposed centrallylof the dies. Four dies are employed as segments combined to circumference the tube interposed between them to form a circumferential corrugation in the tube when the dies are moved toward the axis of'the mandrel. The dies are operated ysimultaneously and cooperate with an anvil upon 'the end of the mandrel within the ating and transmission mechanism in driven connection with a common driving gear, namely gear 10, transmitting the gears 11, 12, 13 and'll, respectively fixed upon.

the ends of the shafts-15, 16, 17 and 18.- These shafts extend longitudinallyA parallel with the mandrel and journalled in bearings inthe front and rear frame walls 36 and 9. As the construction of the diesand the transmission and actuating mechanism of each are the duplicate of one another, `the description thereof be confined lto the singular.

The outer ends of the shafts 15, 16, 17

and 18, are headed, the heads 108 journalling in bearing sockets in the front frame wall 36, and each head is provided with a crank pin 109. The crank pin is engaged into an eccentric bore of a bushing 110 having a portion of its periphery toothed for engagement with an adjusting lug whereby the bushing can be adjusted about the crank for pitman reach regulation. The bushing is engaged within a borel of a split end pitman or eccentric strap 111 and to which the bushing is frictionally clamped, the split portion of the pitm-an having opposing ears or lugs extended therefrom and parallel, through which an adjusting screw 112 is engaged for releasing and clamping the bushing frictionally rigid with the pitman. -The pitman is situated to lie iii a radial positionwvith respect to the axis of the mandrel, and upon rotation of the shaft the crank on the end thereof will impart radial reciprocating motion tothe pitman and parts connected thereto.

The inner end of the pitman 111 termi' nates with a substantially circular or annular head 113 engaging into a socket of a slide'114 of dovetail formation for slidably engaging with and between the opposing guide plates 115-115, removably secured to the front face `of the front frame wall 36. The slide is provided with a removable plate 116 which retains the head 113 of the pitman within the socket of the slide. socket provides suicient clearance for pivotal action of the pitman within the socket. The bushing is retained upon the crank pin against lateral displacement by a washer or disk 118 secured upon the end of the crank .pin by a screw 119, threaded into the crank pin.

With a portion of the bushing periphery provided with gear teeth 120 and the pitman 111 with an aperture 121 as a socket for the axis of an adjusting key 122 adapted to be engaged into the aperture, and having a pinion 123 for working with the teeth of the bushing, the bushing may be rotatably adjusted. For an adjustment, the pitman clamping engagement with the bushing is sufficiently released to permit the bushing to be rotated within the bore of the pitman. The adjustment regulates the reach of the slide and die fixed upon the slide with respect to the anvil mounted upon the end of the mandrel for obtaining the desired com" The receiving a segmental corrugating die 126.

The die constitutes a segmental plate removably secured to the stockl of the slide, and presents a semi-circular edge 127, being of approximately 90 curvature. As shown in Fig. 6, the dies are arranged in opposing pairs with four dies embracing the circumference of the pipe tube to be corrugated. Tneadjacent edges of the dies are formed to include lap joints 128 which serve to maintain proper registration and alignment of the dles as they move toward the axis of the anvil therebetween.

The outer end of the mandrel which pro- 'ects through the opening in the front frame wall 36 is provided with a removable annular anvil consisting of a pair of disks 129, 130. The disk 129 is engaged and nonrotatively fixed upon the end of the mandrel which is counterturned to receive the disk; the second disk, 130, having an eccentric periphery, is fixed to the end of the mandrel by a screw 131 threaded into the end of the mandrel and fixed to the disk 129 by pins 132. vThe lower half of the front face of the disk 130 is ta ered to reduce its thickness to provide or a slight clearance for the metal compressed between the anvil and dies when bending the tube to the form of an elbow, which is bent primarily about the die portion embracing the upper half of the pipe representing the crotch of the elbow. The eccentrieity of the disk 130 provides for a variation in the depth of the corrugations, being more shallow for the back portion of the elbow than vfor the crotch portion, to the formation of a more perfect elbow and bend. The corrugations at the crotch portion being comressed in the bending operation and the olds of the corrugations upon one another while the corrugations at the back of the elbow are spread outwardly.

The disk 129 conforms substantially with the inner diameter of the pipe tube and the metal of the tube is bent about the front edges of the disk. The anvil is removable from the mandrel for interchanging with different diameter anvils for making various pipesizes of elbow.

Bending mechanism.

One end of the pipel tube length is engaged with the carriage and the opposite end has a removable cam ring 133 engaged thereon. The cam rin 133 has its bore counterbored and a steel ushinfr engaged and secured therein, the counterlioring providing an annular recess 134 open to one end of the ring as a socket for engaging the ring Vover the end of the pipe tu e. The ring isof suflicient width to provide for a recess de th for inserting the end of the pipeto a distance to bring the inner edge of the ring approximately at a point where the first corrugation is madel and maintain a true cylindrical thimble end or elbow, and preventing the same from being distorted during thev tube bending operations.

The tube bending ring or head 133 is provided with a pair of diametrically disposed cam lugs 135, each having a curved or cam surface 136 .for engagement respectively with the arms 137-137, which swing inwardly, moving the bending head in for-4 ward and upward directions, expanding the corrugation from one side of the tube and compressing the same atan opposite side as shown in Fig. 8. The bending operation isat a timed period following a corrugating operation and when the pipe tube is gripped by the dies. The corrugations are therefore successively formed and the tube ksuccessively bent into an elbow arc, the arc bearing a relation to the number of circumferential corrugations.

f The arms 137-137 are mounted upon a rock shaft 138 to rock therewith and pivoted each respectively on an axis 139 to swing laterally upon the rock shaft and relatively in opposing direction, adapting the arms to be spread apart for inserting the tube with thebending head 133 upon one end thereof into the machine. The arms swing laterally to clear the cam rings when pressed apart by the cam rings of the bending head when the tube is pushed into 'the machine. Each arm is provided with inclined guide 140 which is engaged by ai respective cam ring1 of the bending head, when the head is force between the arms. The arms are under yielding restraint toward each other so as to be normally in position to engage the cam rin s of the bending head after the tube witi the head attached thereto has been inserted within the machine. For this purpose a spring 141 at one endk is fixed to the rock shaft through the angle iron 142, and the other end of the spring to.' the arm through an angle iron 143.

A lever arm 144 is fixed to the rock shaft 138 between a pair of spaced brackets 145-- 145 fixed to the front end of the bed, which journal end supports the rock shaft. The lever arm 144 extends downwardly and carries a bumper screw 146 which abuttingly engages a p unger bar 147 slidably supported in a bearing bracket 148 fixed to the bed 1 of the machine. (See Fig. 6.) The plunger bar is pivotally connected to the rock lever 149 disposed at an angle upwardly engaged through an opening 150 in the top of the ned and pivoted to a bracketll fixed to the bed by bolts 152. The upper end of the rock lever is provided with a roller 153 engaging tlie cam surface of a cam 154 fixed u on the shaft 18. The cam` actuates the roc lever, imparting motion through the plunger bar 147, lever arm 144, rock shaft 138 to swing the arms 137-137 inwardly for a bending operation, the arms being retracted by a spring 155 having one end connected with the end of the lever arm 144 and its opposite endconnectingvwith the bed of the machine. The sprin holds the arm in engagementwith the p unger bar 147 and thereby serves to yieldingly hold the rock lever149 and its roller 153 against the cam surface of the cam 154. The cam engaging end of the rock lever 149 Ain its retreat position engages against a stop screw 156.

In order to check the momentum of the rotating parts after the power vhas been cut olf, suitable brake mechanism is employed, automatically cont-rolled ywith the control of the clutch, connecting and disconnecting gear 7 from and to the countershaft 8. -The shaft 16 for operating one of the corrugating dies is lprovided with a brake wheel 157 about which a brake yoke engages, consisting of a pair of brake levers 158-158, having a semi-circular portion rigidly connected together and engaged about the brake wheel, each carrying a linin adapted to bear upon the periphery of the brake wheel 157 ,and arm portions 160-160 yieldingly- 'urged toward each other by a spring 161 engaged upon a stem 162 extending through one arm of one of the brake levers and fixed to the arm of the opposite brake lever. The brake ,levers are positively spread apart to release their braking engagement. with the brake wheel by a cam member 163 fixed upon the rod 32 which actuatcs the clutchmechanism for the transmission gearing, the cam member.:1`63 being disposed between the arm portion of the brake levers. Braking one of the shafts of the corrugating dies applies the brake at a location from which the momentum of the rotating parts is more effectively arrested with a minimum braking pressure as the gearing connecting shaft 16 with the countershaft 8 serve as back gears.

Mode f operation.

1 for the desired elbow size, and with the bending vhead 133 engaged over one end thereof, is inserted into the machine between the corrugating dies, with the opposite end of the tube inserted and engaged into the carriage 52 which for `loading is at limit of its foremost traverse upon the mandrel 40. The tube' is engaged in the appropriate annular vsocket or recess in the side of the carriage and locked therein by the`pin 58 afterl the carriage has been manually pushed i rearwardly upon the mandrel to la vstarting position. The operator moving the carria e direction by means of the tue through his hold upon the bending head. The carriage is disengaged from the ratchet bar, by manually throwing the hand lever 77 to slide the latch bolt 72 lifting the pawl 60u from engagement with the ratchet bar.

7* The latch -`bolt remains in its pawl release V stationary trip arm 63a U shoe Y 159- lnecting members 103 and 104 fthe tube for forming a eorrugatiion.v

controlling position until actuated automattion of-the tube the pin or stem 61 of the.

latch'bolt or wedge bar 59 is engaged by the for movlng the latch bolt 59, forwardly depressing the pin 58 to grip the tube and lockingl secure the same to the carriage. At such time the latchbolt 72 is also slid in an I.appropriate direction by thestationary trip*h arm 91 for releasing ghe pawl for cooperation with the ratchet tentlyfeeding the carriage forward.

The carriage in its retreat motion and toward the end thereof actuates the clutch 'shifting bar. 96 through the engagement of the arm or extension 93 of the carriage with :the adjustable dog 95 upon the shifting bar, moving the bar rearwardly, which motion actuates or swings the arm 105 fixed upon the rock shaft or rod 32 -throuvh the con- ;Xed to the shifting rod 96. The rocking motion of the rod 96 operates the clutch mechanism for connecting gear 7 to the countershaft 8 and the transmission remains in commission until the carriage has traveled forward the dist-ance required to form the tube into an elbow. l c l When the clutch has been operated by the carriage for connecting the power to the countershaft, reciprocating movement will beimparted to all of the dies, which is con- 42 upon the mandrel 40, connecting thecarriage with the ratchet bar for intermit pushing the carriage rearward unrugations has been formed in the tube. The eccentric gearing for reciprocating the dies .produces an appropriate dwell to the motion of the dies at the ends of their reciprocating strokes, especially at the end of their forward or compression stroke, to grip the tube and provide a shoulder of the elbow in a bending operation. The timingof the ratchet bar actuation is such that thecarriage and tube will be advanced a step degree after theV dies have been withdrawn suliciently to free the tube and before the dies again compressively engage The lcam 48 is of such formation that it willvmove the ratchet bar forwardly carrying the-carriage therewith and retaining the bar in such advanced position until the tube, is

against which the f corrugations are compressed at the crotch cated by its own eccentric gear,

engaged by the dies to hold the same against retrograde motion, while the ratchet bar retreats sufliciently for a successive tooth engagement of the pawl, or the action of the ratchet bar may be at such a rate due to the formation of the cam which will effect a slight overthrow to the carriage for obtaining a tooth advance of the' pawl with the ratchet bar return stroke ofthe ratchet bar before the dies with the compression engage the tube. The weight 65 holds the pawl against the shoulder of the teeth of the ratchet bar, although the tube and carriage can move forward under the drawing action of the metal during the process of forming a corrugation.

The corrugating dies, each being reciprocan be independently adjusted and timed for producing a corrugation varying in channel depth circumferentially of the tube, most appropriate for the bending operation, without shearing or tearing the metal in either the corrugating or bending operation and produce ahigh quality product.

With the employment of four dies a very uniform compression is obtained circumferentially about the tube, avoiding twisting of the tube which would be detrimental to the angle of the elbowv and destroy its axial al1 nment from one end to the other.

t an appropriately timed interval after the completion of a corrugation operation the bending arms move the bending head to move forwardly and upwardly in a short radius, due to the cam surface of the cam lugs sliding upon the arms, resulting in pressing the corrugation for a p ortion nearest the axis of the bending radius together while an opposite portion of the corrugation is expanded. The corrugating and bending operation following in rapid succession for the required number necessary to produce the desired angle of elbow, which when reached obtains a carriage advance suilicient to bring the carriage into cooperation with the clutch shifting bar trippin member 94: for a clutch control to throw o the powerA to shaft 8, and an application of the brake and also for tripping the latch bar 59 to release the lock pin 58 from engagement with the tube; whereupon the finished elbow is withdrawn from the carriage with the parts in position for operation upon a second tube.

Having described my invention, I claim:

1. a machine of the character disclosed, a carriage for intermittently advancing a sheet metal cylindrical tube, means for circumferentially corrugating said tube, and means for bendin the tube to an elbow angle successiveto teformation of a corrugation, comprising a head member engaged upon the end o the tube, a pair of spaced arms swinging to engage said head member Vof a pipe section. forwardly, causing the tube section forward, bending means for forming the corrugated tube into an elbow,

comprising a pair of arms oscillating as a unit at an angle to the direction of tube section feed, to 4engage a head member on the end of the tube section to move the same in an arc, said arms being hinged for swinging the same apart for tube and head insertion into the operative portion, means for oscillating said arms in timed relation to the corrugating dies, and said head member detachably secured upon the end of the tube section cooperating with said arms.

In a machine of the class described, bending mechanism, a member adapted to be detachably engaged upon the end of a sheet metal pipe section for cooperation with said bending mechanism to bend the pipe section to an elbow angle, comprising an annulus having a pair of diametrically disposed radial cam lugs extending therefrom, a collar secured within said annulus, said annulus and collar arranged to provide a circumferential recess therebetween to receive the end 4. In a machine of the class described, bending mechanism, a member adapted to be detachably engaged upon the end of a sheet metal pipe section to provide a head for cooperating with said bending mechanism to bend the pipe section to an elbow angle, comprising a plurality of concentrically unite annuli and providing an annular recess therebetween open to one end for insertion upon the end of a pipe section, and a pair of radial cam lugs projecting from the outer annulus for engagement with the bending mechanism for moving the head member in an arc and thereby bend the pipe.

'5. In a machine of the character disclosed, means for circumferentially corrugating a sheet metal pipe section, a carriage movable from and toward said corrugating means for receiving and advancing the pipe section to said corrugating means having a plurality of different diameter recesses open to one end of the carriage respectively for inserting different diameter sizes of pipe section into the carriage, a pin capable of being projected into a recess to hold the pipe firmly in place, a slide member for alternately depressing or releasing said pin, and means disposed at the fore and aft carriage traversing limits for'automatically operating said slide member in alternate stroke motion. J

6. In a machine of the character disclosed, reciprocating dies. for circumferentially corrugating a sheet metal pipe section, a mandrel sustained for engagement into the pipe section having an anvil on the end thereof for cooperating With said dies, a reciprocating ratchet bar carried by said mandrel, a carriage translatable upon said mandrel in forward and retreat stroke directions receiving and feeding the pipe section to the corrugating dies, a pawl carried by Said carriage adapted to cooperate with said ratchet bar, va latch member movable transversely to the pawl for denormalizing said pawl, and means for automatically actuating said latch member for normalizing said pawl at the end of a retreat stroke of said carriage.

7. In a machine of the character disclosed, means for circumferentially corrugating a sheet metal pipe section, a mandrel sustained for engagement into the pipe section having an anvil on the end thereof for cooperation with said corrugating means, a reciprocating. ratchet bar longitudinally slidable upon said mandrel, a carnage translatable upon said mandrel toward and from said corrugating means and having a yielding pawl enga cable with said ratchet bar, a rotative cam or reciprocating said ratchet bar, transmissiony gearing including a clutch for transmitting said rotative cam, and clutch controlling means operative by Said carriage at its fore and aft limits of motion upon said mandrel.

8. In a machine of the class described, means for circumferentially corrugating a sheet metal pipe, a carriage movable in opposite directions for receiving the pipe and feeding the same to said corrugating means, said carriage having an annular recess into which one end of the pipe is engaged, apin carried by said carriage movable to engage and secure the pipe in its engagement with the carriage, and a slide member mounted in said carriage reciprocable for actuating and releasing said pin.

9. In a machine of the class described, means for circumferentiall'y corrugating a sheet metal pipe, a carriage movable in opposite directions for receiving the pipe and feeding the same to said corrugating means, said carriage having an annular recess into which one end of the pipe is engaged,a pin carried by said carriage movable to engage and secure the pipe in its engagement With the carriage, and a slide member mounted in said carriage reciprocable for actuating and releasing said pin and in a direction length- Wise with the carriage motion for automatic control by independently arresting its motion with the carriage.

In witness whereof, I Ahereunto subscribe my naine.

CHARLES J. HOLUB. 

